NASA announced Wednesday, July 31 that the space agency had concluded the preliminary design review for the Space Launch System (SLS), which includes the system’s design, production, and ground support plans. Over at the space agency’s Michoud Assembly Facility (MAF), located in New Orleans, La., the first liquid hydrogen tank barrel segment for the core stage of SLS was completed. In short, the elements of NASA’s new heavy-lift booster, be they managerial or hardware-based, are coming together.
The review concluded SLS’ initial design and development phase. The next phase, termed Key Decision Point-C, will move the program from this review to being implemented. NASA program members discussed how the completed review will contribute to the development of SLS.
Video courtesy of NASA Marshall
“The review had to be incredibly detailed, so our plans for vehicle integration, flight software, test, verification, and operations will result in a safe, affordable, and sustainable vehicle design,” said Todd May, manager of the SLS Program.
Experts from 11 different review teams participated in the review process, which included approximately 200 documents and 15 terabytes of data. The Boeing Corporation, ATK and Aerojet Rocketdyne—NASA’s industry partners—also contributed to this milestone and will continue to work on the program.
“The agency not only reviews the program internally, but also seeks help from many external sources. There are several external NASA stakeholders and organizations—including Congress, the Office of Management and Budget, and the public—who require a thorough, truly independent look at these programs as they transition through their lifecycle,” said LeRoy Cain, who leads the independent review board for SLS.
As NASA was working on ensuring that its new heavy-lift booster meets its requirements on paper, the agency, along with The Boeing Company, was “bending metal” as it began constructing the first SLS.
AmericaSpace was at Michoud and Stennis for the ribbon-cutting ceremony for the new welding machine that helped build this tank. In mid-June, AmericaSpace’s editor, Jason Rhian, toured both MAF as well as nearby Stennis Space Center.
The recently-constructed segment is what is known as a “confidence” barrel. This is due to the fact that it helps confirm the newly-unveiled vertical weld center is working as advertised. This new tool is a friction-stir welder which is used to construct both wet and dry structures on the SLS core stage.
As the name implies, friction-stir welding uses heat created by friction, along with forging pressure, to produce extremely strong bonds that have few, if any, defects. Using this process the metals used are converted to what NASA calls a “plastic-like” state. To bond two metal sections together, a pin-like tool rotates to soften, stir, and then forge the bond between plates. One of the benefits of this method is that it produces a clean and relatively uniform weld. NASA views this as important in the development of next-generation space hardware.
“This barrel section was welded as part of a plan to demonstrate new weld tool manufacturing capabilities and will be used for further production tool confidence welding activities,” said Steve Holmes, manufacturing lead in the Stages Office at NASA’s Marshall Space Flight Center. “The first fully welded barrel segments are extremely important to test tools and manufacturing processes prior to start of qualification hardware and first-flight articles.”
The SLS Program was proposed two years ago, as the STS Program (more familiarly known as the space shuttle program) came to its end. In July 2012, the program completed a combined system requirements review and system definitions review, which confirmed SLS could move from initial concepts to design. Element-level reviews have been completed for several SLS components, including its core stage, boosters, engines, spacecraft, and payload integration systems.
The completion of the review and the first hydrogen tank comes on the heels of a previous NASA announcement that a review of asteroid capturing techniques had also been finished. The design review will aid the development of possible future manned asteroid missions, to be developed during NASA’s FY-2014. SLS is scheduled to launch its first test flight in 2017, carrying an unmanned Orion spacecraft. Its modified 130-metric-ton version is proposed to launch 286,000 pounds into orbit, making it the most powerful rocket ever built. This configuration is meant to launch missions—manned and unmanned—into deep space. The newly-welded component will help to ensure the success of these missions.
When in place, the SLS heavy-lift vehicle—slated to be 321 feet tall—will be able to provide 8.4 million pounds of thrust at liftoff and will be capable of lifting 154,000 pounds into space. The SLS system, along with the Orion spacecraft, is intended to make deep-space missions to asteroids—and perhaps, one day, Mars—a possibility.
“In two short years from the first announcement of the Space Launch System, we are at a milestone that validates the detailed design and integration of the system. You can feel the momentum of the workforce as we produce test hardware today. We are creating a national capability, and we will get this country, and the world, exploring deep space,” said Dan Dumbacher, deputy associate administrator for the Human Exploration and Operations Mission Directorate.
Want to keep up-to-date with all things space? Be sure to “Like” Retro Space Images & AmericaSpace on Facebook and follow us on Twitter: @AmericaSpace